How long should antibiotics be stopped prior to bone biopsy?

• A. 24 hours
• B. 72 hours
• C. 48 hours
• D. Never stop antibiotics

Answer: (C)

The idea here is to maximize the chance of obtaining a true culture from the bone biopsy. Antibiotics in the system can suppress bacterial growth in culture, leading to false-negative results. Stopping therapy for about 48 hours before taking the biopsy allows drug levels to fall enough that organisms can grow in the culture, improving diagnostic accuracy, while not leaving the infection untreated for too long in most cases. A shorter 24-hour window might still leave residual antibiotic levels that blunt growth, while a 72-hour window could risk progression of infection or patient instability. Never stopping antibiotics would likely reduce the usefulness of the culture result. If a patient is on long-acting agents or is acutely ill, the plan should be individualized with infectious disease input, but 48 hours is the typical rule of thumb.